many of the awards handed out today were a result from actions taken during the city's largest ever mass killings that happened at oikos university earlier this year. >>> i'm juliette goodrich. an unidentified couple walks into walmart and randomly pays for customers' items in their carts. who are these secret santas? the story coming up. >>> and later this week, it will be no ordinary tide. what makes a king tide and how it can show us the bay area's future. >> not one, not two, and not even three, but a series of storms heading this way. we'll track them together as eyewitness news continues right here on cbs 5. ,,,,,,,,,,,,,, and couple of very generouss paid a visit to a bay area walmart. juliette goodrich is in livermore, where the man and woman picked shoppers at ra, and... well juliette.. you l it.... >>> 'tis the season for secret santas. a couple of generous ones paid a visit to an area walmart. juliette goodrich reports. >> reporter: this is one of the holiday stories we love to report on. imagine walking into walmart buying your holiday goodies and someone saying, i'll pick up